IsLowercase method using string::find_first_not_of

[BercutSh]

Good day!
I’ve tried to find a way to check all the special characters not only spaces or \0 case and found two solutions on StackOverflow. The one is to use string::find_first_not_of and type all the letters I want allow to pass through my function. It doesn’t look neat, but it works.

https://gist.github.com/BercutSh/9ea0bb58c644e322f40006cf17f85749

The second way is using the regular expression pattern like [a-z].
So what do you think about advantages and disadvantages of these methods?

UPD: Just realized that islower() has the same effect and doesn’t allow to use special characters

[arhiDavid]

Hello! I came to the same solution and wanted to brag about it, but it seems you have beat me to it

But it looks like your method is more efficient than mine.
I too would like to know if there are some disadvantages to using this method.